diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5692fe54..3830190f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,8 @@
 
 * Added a "prefix" option in case you want to use a different version of serializer.
 
+* Serializers default namespace can be set in `default_serializer_options` and inherited by associations.
+
 # VERSION 0.8.1
 
 * Fix bug whereby a serializer using 'options' would blow up.
diff --git a/lib/action_controller/serialization.rb b/lib/action_controller/serialization.rb
index 5b2a3d35..7ff06950 100644
--- a/lib/action_controller/serialization.rb
+++ b/lib/action_controller/serialization.rb
@@ -80,6 +80,7 @@ module ActionController
 
     def build_json_serializer(resource, options = {})
       options = default_serializer_options.merge(options)
+      @namespace_for_serializer = options.fetch(:namespace, nil)
 
       if serializer = options.fetch(:serializer, default_serializer(resource))
         options[:scope] = serialization_scope unless options.has_key?(:scope)
diff --git a/lib/active_model/array_serializer.rb b/lib/active_model/array_serializer.rb
index aabfb651..91b61b6a 100644
--- a/lib/active_model/array_serializer.rb
+++ b/lib/active_model/array_serializer.rb
@@ -35,7 +35,7 @@ module ActiveModel
 
     def serializer_for(item)
       serializer_class = @each_serializer || Serializer.serializer_for(item, namespace: @namespace) || DefaultSerializer
-      serializer_class.new(item, scope: scope, key_format: key_format, only: @only, except: @except, polymorphic: @polymorphic)
+      serializer_class.new(item, scope: scope, key_format: key_format, only: @only, except: @except, polymorphic: @polymorphic, namespace: @namespace)
     end
 
     def serializable_object
diff --git a/lib/active_model/serializer.rb b/lib/active_model/serializer.rb
index 8281b495..d5bd0028 100644
--- a/lib/active_model/serializer.rb
+++ b/lib/active_model/serializer.rb
@@ -131,6 +131,7 @@ end
       @except        = options[:except] ? Array(options[:except]) : nil
       @key_format    = options[:key_format]
       @context       = options[:context]
+      @namespace     = options[:namespace]
     end
     attr_accessor :object, :scope, :root, :meta_key, :meta, :key_format, :context, :polymorphic
 
@@ -216,7 +217,8 @@ end
     end
 
     def association_options_for_serializer(association)
-      prefix = association.options[:prefix]
+      prefix    = association.options[:prefix]
+      namespace = association.options[:namespace] || @namespace || self.namespace
 
       { scope: scope }.tap do |opts|
         opts[:namespace] = namespace if namespace
diff --git a/test/integration/action_controller/namespaced_serialization_test.rb b/test/integration/action_controller/namespaced_serialization_test.rb
index 4a5fbbf9..1e758d29 100644
--- a/test/integration/action_controller/namespaced_serialization_test.rb
+++ b/test/integration/action_controller/namespaced_serialization_test.rb
@@ -43,5 +43,54 @@ module ActionController
         assert_serializer CommentSerializer
       end
     end
+
+    class OptionNamespacedSerializationTest < ActionController::TestCase
+      class MyController < ActionController::Base
+        def default_serializer_options
+          {
+            namespace: TestNamespace
+          }
+        end
+
+        def render_profile_with_namespace_option
+          render json: Profile.new({ name: 'Name 1', description: 'Description 1'})
+        end
+
+        def render_profiles_with_namespace_option
+          render json: [Profile.new({ name: 'Name 1', description: 'Description 1'})]
+        end
+
+        def render_comment
+          render json: Comment.new(content: 'Comment 1')
+        end
+
+        def render_comments
+          render json: [Comment.new(content: 'Comment 1')]
+        end
+      end
+
+      tests MyController
+
+      def test_render_profile_with_namespace_option
+        get :render_profile_with_namespace_option
+        assert_serializer TestNamespace::ProfileSerializer
+      end
+
+      def test_render_profiles_with_namespace_option
+        get :render_profiles_with_namespace_option
+        assert_serializer TestNamespace::ProfileSerializer
+      end
+
+      def test_fallback_to_a_version_without_namespace
+        get :render_comment
+        assert_serializer CommentSerializer
+      end
+
+      def test_array_fallback_to_a_version_without_namespace
+        get :render_comments
+        assert_serializer CommentSerializer
+      end
+    end
+
   end
 end
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